While the anatomical structure of most individuals' brains is very similar, the functional arrangement of different individuals' brains are as unique as a fingerprint. This leads to the general problem in neuroscience that clinicians and doctors can easily identify abnormalities and traumas such as blood clots, tumors and stroke damage based on their understanding of brain anatomy. However, they currently have no way of visually determining the functions of the brain matter in and around those abnormalities and trauma.
Neurosurgeons are easily able to use existing technology such as MRI's to determine the location of a tumor in a patient's brain. Based on the location of a tumor a surgeon can plan what they think with be the best route for getting to and removing the tumor. However, what they cannot determine are things like how much brain matter around the tumor they can remove without substantially affecting the patient's functions, how the route to the tumor may go through critical areas which could easily be avoided by a different path, how the removal of the tumor will affect a patient's functions, etc.
One method Neurosurgeons have to mitigate some of these risks is direct electrical stimulation of the brain during surgery. By exposing a portion of a brain to an electrical current it is possible for the surgeon to make a judgment about the function of that portion of the brain. When testing for a motor response this can work well as it is easy to visually determine, or measure, a person's physical responses. For example, the assistant can see if the patient's finger moves in response to a stimulation.
Many drawbacks arise from such direct stimulation methods. For one, any time spent during surgery testing brain functions is taken away from the actual removal of a tumor or other surgical function. As patient risk is directly correlated to the length of a surgery, this is a factor that needs to be mitigated. Therefore there exists a clear need for a non-surgical method of accurately determining brain functions.
Another major drawback of current methods is that it is while it is relatively easy to test motor functions it is extremely difficult to accurately test cognitive functions. Therefore, there exists a need to accurately test one or more cognitive functions, such as, for example speech, language, working-memory, decision-making, etc.
Furthermore, while these problems exist and arise in the context of surgery and surgical planning, the use of an applicable solution can be extended to non-surgical situations. For example, during therapy it can be extremely useful to be able to accurately track progress or deterioration of cognitive functions. This can be helpful in both a clinical situation to test a patient's response to therapy as well as in a research situation to test if a therapy functions as it should.